Oral Intimidation a T?

[JeffW]

I coach in a rec league (girls 11-13) that requires us coaches to ref other games in our league. Many of the coaches balk at the requirement (they're sort of tricked into it), but I actually like it.

I'm scheduled to ref a game this Saturday involving a coach who I'm told has instructed his players to intimidate the ball handler coming across half court by running at her, arms up and waving, and making a lot of sudden, startling noise. To me, an untrained ref, this sounds like noise that serves no basketball purpose (no communication value). It's just calculated to intimidate.

Is this kind of intimidation illegal? If I'm prepared to prevent it or penalize it, is it a T? Should I warn the coach before the game so he can rescind his instructions to his players?